Contacts of the helix formed by residues 139 - 168 (chain B) in PDB entry 2Y4T


Residue contacts within the protein are derived with the CSU software (Sobolev V., Sorokine A., Prilusky J., Abola E.E. and Edelman M. (1999) Automated analysis of interatomic contacts in proteins. Bioinformatics, 15, 327-332). A short description of the analytical approach is given at the end of the page.
For CSU analysis of other PDB entry

Note:
Non-standard 3 letter residue codes indicate a heterogroup. To identify and analyse, use LPC software

Legend:
Dist - nearest distance (Å) between atoms of two residues
Surf - contact surface area (Å2) between two residues
HB   - hydrophilic-hydrophilic contact (hydrogen bond)
Arom - aromatic-aromatic contact
Phob - hydrophobic-hydrophobic contact
DC   - hydrophobic-hydrophilic contact (destabilizing contact)
+/-  - indicates presence/absence of a specific contacts
*    - indicates residues forming contacts  by their side chain
       (including CA atoms)
Residues in contact with ASN 139 (chain B).
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    137B  SER*     3.0     9.6    +      -       -      +
    138B  GLU*     1.3    77.2    -      -       -      +
    140B  GLU*     1.3    61.9    +      -       +      +
    141B  GLU      3.3     1.2    +      -       -      -
    142B  LYS*     3.8    17.7    +      -       -      +
    143B  GLU*     4.2     8.8    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLU 140 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    105B  THR*     3.5    18.5    +      -       -      -
    106B  ALA*     3.5    31.3    +      -       -      +
    109B  LEU*     3.8    23.4    -      -       +      +
    131B  VAL*     4.8     4.2    -      -       +      +
    136B  PRO*     3.7     8.6    -      -       +      +
    137B  SER*     2.7    46.7    +      -       -      +
    139B  ASN*     1.3    72.1    -      -       +      +
    141B  GLU*     1.3    62.8    +      -       -      +
    142B  LYS      3.3     0.2    -      -       -      -
    143B  GLU*     3.5     3.6    +      -       -      +
    144B  ALA*     3.0    24.8    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLU 141 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    132B  LEU*     4.2    17.4    -      -       +      +
    136B  PRO*     3.7    31.3    -      -       +      +
    137B  SER      3.3     7.2    +      -       -      +
    138B  GLU*     3.7    24.8    -      -       -      +
    139B  ASN      3.3     0.4    -      -       -      -
    140B  GLU*     1.3    78.1    -      -       -      +
    142B  LYS*     1.3    63.6    +      -       +      +
    144B  ALA*     3.4     1.1    +      -       -      +
    145B  GLN*     2.9    45.6    +      -       +      +
----------------------------------------------------------
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Residues in contact with LYS 142 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    138B  GLU*     3.0    48.0    +      -       -      +
    139B  ASN*     4.2    14.0    +      -       -      +
    140B  GLU      3.3     0.6    -      -       -      -
    141B  GLU*     1.3    85.5    +      -       +      +
    143B  GLU*     1.3    63.1    +      -       +      +
    145B  GLN*     4.2     4.6    -      -       -      +
    146B  SER*     3.2    26.5    +      -       -      -
----------------------------------------------------------
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Residues in contact with GLU 143 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    109B  LEU*     4.5    11.1    -      -       +      +
    113B  HIS*     3.2    34.7    +      -       +      +
    139B  ASN      4.2     5.7    +      -       -      +
    140B  GLU*     3.5     8.7    +      -       -      +
    141B  GLU      3.3     0.2    -      -       -      -
    142B  LYS*     1.3    76.2    -      -       +      +
    144B  ALA*     1.3    65.9    +      -       -      +
    145B  GLN      3.2     0.2    +      -       -      -
    146B  SER*     3.3     2.9    +      -       -      -
    147B  GLN*     3.0    31.4    +      -       -      +
----------------------------------------------------------
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Residues in contact with ALA 144 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    109B  LEU*     3.7    23.8    -      -       +      +
    128B  PHE*     3.6    27.7    -      -       +      +
    131B  VAL*     3.9    12.3    -      -       +      -
    132B  LEU*     3.8    19.5    -      -       +      -
    140B  GLU      3.0    17.9    +      -       -      +
    141B  GLU*     3.7     4.0    -      -       -      +
    143B  GLU*     1.3    76.3    -      -       -      +
    145B  GLN*     1.3    59.9    +      -       -      +
    148B  LEU*     3.6    15.7    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLN 145 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    132B  LEU*     3.8    26.5    -      -       +      +
    141B  GLU*     2.9    29.1    +      -       -      +
    142B  LYS*     4.2     4.5    -      -       -      +
    144B  ALA*     1.3    74.0    -      -       -      +
    146B  SER*     1.3    64.6    +      -       -      +
    147B  GLN      3.2     1.6    -      -       -      -
    148B  LEU*     3.0    21.2    +      -       +      +
    149B  ILE*     3.2    17.4    +      -       +      +
----------------------------------------------------------
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Residues in contact with SER 146 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    142B  LYS      3.2    18.4    +      -       -      -
    143B  GLU*     4.0     3.6    -      -       -      -
    145B  GLN*     1.3    78.2    -      -       -      +
    147B  GLN*     1.3    57.9    +      -       -      +
    149B  ILE*     3.2    13.1    +      -       -      +
    150B  LYS*     3.1    46.7    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLN 147 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    113B  HIS*     3.1    42.7    +      -       +      +
    116B  LEU*     3.3    22.5    -      -       -      +
    128B  PHE*     3.2    31.2    -      -       +      -
    143B  GLU*     3.0    21.8    +      -       -      +
    144B  ALA      4.0     1.1    -      -       -      +
    146B  SER*     1.3    77.9    -      -       -      +
    148B  LEU*     1.3    55.1    +      -       -      +
    150B  LYS*     3.4    37.3    +      -       -      +
    151B  SER*     2.8    29.1    +      -       -      -
    183B  VAL*     5.5     0.6    -      -       -      +
----------------------------------------------------------
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Residues in contact with LEU 148 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    125B  GLU*     3.9    34.5    -      -       +      +
    128B  PHE*     3.5    28.3    -      -       +      -
    129B  LYS*     4.3    19.7    -      -       +      -
    132B  LEU*     4.0    23.3    -      -       +      -
    144B  ALA      3.6    11.6    +      -       -      +
    145B  GLN*     3.0    11.7    +      -       +      +
    147B  GLN*     1.3    76.5    -      -       -      +
    149B  ILE*     1.3    61.4    +      -       +      +
    151B  SER*     3.7     2.2    -      -       -      -
    152B  ASP*     2.8    44.9    +      -       -      +
----------------------------------------------------------
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Residues in contact with ILE 149 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    145B  GLN*     3.6    14.6    -      -       +      +
    146B  SER*     3.2    13.8    +      -       -      +
    148B  LEU*     1.3    77.3    -      -       +      +
    150B  LYS*     1.3    63.8    +      -       +      +
    152B  ASP*     3.7    10.2    +      -       -      +
    153B  GLU*     3.5    17.3    +      -       -      +
----------------------------------------------------------
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Residues in contact with LYS 150 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    116B  LEU*     4.6     1.1    -      -       +      -
    146B  SER*     3.1    34.0    +      -       -      +
    147B  GLN*     3.4    36.8    -      -       -      +
    149B  ILE*     1.3    77.2    -      -       +      +
    151B  SER*     1.3    57.7    +      -       -      +
    153B  GLU*     3.1     9.3    +      -       -      +
    154B  MET*     2.9    35.0    +      -       +      +
    183B  VAL*     4.2    34.8    -      -       +      -
----------------------------------------------------------
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Residues in contact with SER 151 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    116B  LEU*     3.8    26.0    -      -       -      +
    121B  LEU*     4.1     9.7    +      -       -      +
    125B  GLU*     3.2    31.8    +      -       -      +
    128B  PHE*     4.8     4.3    -      -       -      -
    147B  GLN      2.8    21.1    +      -       -      -
    148B  LEU*     3.3     8.3    +      -       -      -
    150B  LYS*     1.3    73.8    -      -       -      +
    152B  ASP*     1.3    58.3    +      -       -      +
    154B  MET*     3.3     5.0    +      -       -      +
    155B  GLN*     3.0    29.6    +      -       -      +
----------------------------------------------------------
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Residues in contact with ASP 152 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    125B  GLU*     3.6    18.7    -      -       -      +
    148B  LEU*     2.8    32.1    +      -       -      +
    149B  ILE*     3.9    11.8    -      -       -      +
    151B  SER*     1.3    71.6    -      -       -      +
    153B  GLU*     1.3    61.8    +      -       -      +
    155B  GLN*     3.4    16.4    -      -       -      +
    156B  ARG*     3.4     8.0    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLU 153 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    149B  ILE      3.5     9.4    +      -       -      +
    150B  LYS*     3.1     8.5    +      -       -      +
    152B  ASP*     1.3    75.2    -      -       -      +
    154B  MET*     1.3    77.0    +      -       -      +
    155B  GLN      3.2     0.2    -      -       -      -
    156B  ARG*     3.0    26.5    +      -       -      +
    157B  LEU*     2.8    53.3    +      -       +      +
    179B  LYS*     4.8    10.6    +      -       -      +
----------------------------------------------------------
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Residues in contact with MET 154 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    116B  LEU*     4.7     1.1    -      -       +      -
    121B  LEU*     3.7    21.0    -      -       +      +
    150B  LYS*     2.9    25.2    +      -       +      +
    151B  SER*     3.5    10.8    -      -       -      +
    153B  GLU*     1.3   100.7    -      -       -      +
    155B  GLN*     1.3    53.7    +      -       -      +
    157B  LEU*     3.2    15.9    +      -       +      +
    158B  ARG*     2.8    36.2    +      -       -      +
    179B  LYS      4.1     3.8    -      -       -      +
    180B  ILE*     3.7    33.2    -      -       +      +
    183B  VAL*     3.8    36.8    -      -       +      -
    184B  CYS*     4.1    12.1    -      -       -      -
----------------------------------------------------------
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Residues in contact with GLN 155 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    121B  LEU*     3.4    31.5    -      -       -      +
    122B  ASP*     2.9    24.2    +      -       -      +
    125B  GLU*     2.8    29.3    -      -       -      +
    151B  SER      3.0     8.9    +      -       -      +
    152B  ASP*     3.4    13.7    -      -       -      +
    153B  GLU      3.2     0.2    -      -       -      -
    154B  MET*     1.3    77.1    -      -       -      +
    156B  ARG*     1.3    59.7    +      -       -      +
    158B  ARG*     3.9     7.2    -      -       -      +
    159B  SER*     3.4    21.8    +      -       -      -
----------------------------------------------------------
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Residues in contact with ARG 156 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    152B  ASP      3.4     8.1    +      -       -      +
    153B  GLU*     3.0    27.5    +      -       +      +
    155B  GLN*     1.3    79.1    -      -       -      +
    157B  LEU*     1.3    61.9    +      -       +      +
    159B  SER*     3.5     6.8    +      -       -      -
    160B  GLN*     3.1    46.2    +      -       +      +
----------------------------------------------------------
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Residues in contact with LEU 157 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    153B  GLU*     2.8    36.8    +      -       +      +
    154B  MET*     3.6    30.3    -      -       +      +
    156B  ARG*     1.3    75.8    -      -       +      +
    158B  ARG*     1.3    58.8    +      -       -      +
    160B  GLN*     3.3     9.4    +      -       -      +
    161B  ALA*     2.8    31.4    +      -       -      +
    176B  PHE*     3.7    30.8    -      -       +      +
    179B  LYS*     3.7    38.6    -      -       +      -
    180B  ILE*     3.5    19.3    -      -       +      +
----------------------------------------------------------
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Residues in contact with ARG 158 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    119B  GLY*     3.4    25.3    +      -       -      -
    121B  LEU*     4.2    18.1    -      -       +      +
    154B  MET      2.8    19.3    +      -       -      +
    155B  GLN*     3.9     9.2    -      -       -      +
    156B  ARG      3.4     0.2    -      -       -      -
    157B  LEU*     1.3    72.5    -      -       -      +
    159B  SER*     1.3    62.8    +      -       -      +
    161B  ALA*     3.3     1.7    +      -       -      +
    162B  LEU*     3.0    50.1    +      -       +      +
    180B  ILE*     3.9    14.0    -      -       +      +
    187B  ASP*     3.5    18.0    +      -       -      -
    189B  GLU*     5.4     6.5    -      -       -      +
    190B  LEU*     3.6    25.6    -      -       +      +
----------------------------------------------------------
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Residues in contact with SER 159 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    155B  GLN      3.4    11.1    +      -       -      -
    156B  ARG*     3.7    10.3    -      -       -      -
    157B  LEU      3.4     0.4    -      -       -      -
    158B  ARG*     1.3    78.9    -      -       -      +
    160B  GLN*     1.3    58.0    +      -       -      +
    162B  LEU*     4.1     7.3    -      -       -      +
    163B  ASN*     3.0    30.5    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLN 160 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    156B  ARG*     3.1    48.7    +      -       +      +
    157B  LEU*     3.7     7.2    -      -       -      +
    158B  ARG      3.2     0.2    -      -       -      -
    159B  SER*     1.3    75.9    -      -       -      +
    161B  ALA*     1.3    55.6    +      -       -      +
    163B  ASN*     3.4     9.9    +      -       +      +
    164B  ALA*     2.7    37.4    +      -       -      +
    176B  PHE*     3.3    48.3    -      -       +      -
----------------------------------------------------------
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Residues in contact with ALA 161 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    157B  LEU      2.8    20.6    +      -       -      +
    158B  ARG*     3.7     3.1    -      -       -      +
    160B  GLN*     1.3    72.3    -      -       -      +
    162B  LEU*     1.3    59.7    +      -       +      +
    164B  ALA*     3.7     2.5    -      -       -      +
    165B  PHE*     3.1    27.4    +      -       -      +
    173B  ALA*     3.8     6.5    -      -       -      +
    176B  PHE*     3.9    16.5    -      -       +      +
    177B  LEU*     3.9    23.3    -      -       +      -
    180B  ILE*     3.6    20.6    -      -       +      -
    190B  LEU*     5.2     2.0    -      -       +      -
    193B  LEU*     4.5     3.5    -      -       -      +
----------------------------------------------------------
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Residues in contact with LEU 162 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    158B  ARG*     3.0    48.8    +      -       +      +
    159B  SER*     4.1     5.6    -      -       -      +
    161B  ALA*     1.3    73.1    -      -       -      +
    163B  ASN*     1.3    55.4    +      -       -      +
    165B  PHE*     3.1     6.6    +      -       +      +
    166B  GLY*     2.7    34.3    +      -       -      -
    190B  LEU*     4.7    10.3    -      -       +      -
    193B  LEU*     4.0    23.1    -      -       +      -
----------------------------------------------------------
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Residues in contact with ASN 163 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    159B  SER*     3.0    21.2    +      -       -      +
    160B  GLN*     3.4    12.1    +      -       -      +
    162B  LEU*     1.3    74.9    -      -       -      +
    164B  ALA*     1.3    64.8    +      -       -      +
    166B  GLY*     3.3     2.6    +      -       -      +
    167B  SER*     3.3    25.7    +      -       -      -
    176B  PHE*     6.4     0.2    -      -       -      -
----------------------------------------------------------
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Residues in contact with ALA 164 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    160B  GLN      2.7    21.1    +      -       -      +
    161B  ALA      3.7     3.6    -      -       -      +
    163B  ASN*     1.3    77.0    -      -       -      +
    165B  PHE*     1.3    60.9    +      -       -      +
    167B  SER*     3.2    10.9    +      -       -      -
    169B  ASP*     2.9    44.6    +      -       +      +
    172B  ALA*     4.1    10.3    -      -       +      -
    173B  ALA*     3.7    17.5    -      -       -      +
    176B  PHE*     4.2     7.4    -      -       +      -
----------------------------------------------------------
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Residues in contact with PHE 165 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    161B  ALA      3.1    18.5    +      -       -      +
    162B  LEU*     3.5     4.5    -      -       -      +
    164B  ALA*     1.3    75.8    -      -       -      +
    166B  GLY*     1.3    68.6    +      -       -      +
    168B  GLY*     3.1    14.6    +      -       -      -
    169B  ASP      4.5     3.4    -      -       -      +
    170B  TYR*     3.7    29.9    -      +       -      -
    173B  ALA*     4.0     6.4    -      -       +      +
    193B  LEU*     4.0    35.0    -      -       +      -
    196B  GLU*     3.9    28.9    -      -       +      -
    197B  CYS*     3.5    27.1    -      -       -      -
    200B  LYS*     5.8     0.4    -      -       +      -
----------------------------------------------------------
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Residues in contact with GLY 166 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    162B  LEU      2.7    19.0    +      -       -      -
    163B  ASN*     3.3     3.3    +      -       -      -
    165B  PHE*     1.3    80.6    -      -       -      +
    167B  SER*     1.3    58.5    +      -       -      +
    168B  GLY*     3.5     0.5    +      -       -      -
----------------------------------------------------------
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Residues in contact with SER 167 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    163B  ASN*     3.3    13.2    +      -       -      -
    164B  ALA*     3.2    14.6    +      -       -      -
    165B  PHE      3.3     0.2    -      -       -      -
    166B  GLY*     1.3    75.9    -      -       -      +
    168B  GLY*     1.3    56.6    +      -       -      +
    169B  ASP*     3.6    10.0    +      -       -      +
----------------------------------------------------------
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Residues in contact with GLY 168 (chain B). Click here for Legend to table.
----------------------------------------------------------
                                  Specific contacts
                               ---------------------------
     Residue       Dist    Surf   HB    Arom    Phob    DC
----------------------------------------------------------
    164B  ALA      3.9     0.2    -      -       -      -
    165B  PHE      3.1    13.2    +      -       -      -
    166B  GLY      3.3     1.0    -      -       -      -
    167B  SER*     1.3    78.1    -      -       -      +
    169B  ASP*     1.3    58.9    +      -       -      +
    170B  TYR*     3.3    35.0    +      -       -      -
----------------------------------------------------------
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A short description of the analytical approach
The contact analysis used in this page is based upon the approach developed in: Sobolev V., Wade R.C., Vriend G. and Edelman M. PROTEINS (1996) 25, 120-129. Contact legitimacy depends on the hydrophobic-hydrophilic properties of the contacting atoms. In order to define it, for each inter-atomic contact, eight atom classes have been introduced:


   I  Hydrophilic      - N and O that can donate and accept hydrogen bonds
                         (e.g., oxygen of hydroxyl group of Ser. or Thr)
  II  Acceptor         - N or O that can only accept a hydrogen bond
 III  Donor            - N that can only donate a hydrogen bond
  IV  Hydrophobic      - Cl, Br, I and all C atoms that are not in
                         aromatic rings and do not have a covalent bond to
                         a N or O atom
   V  Aromatic         - C in aromatic rings irrespective of any other 
                         bonds formed by the atom
  VI  Neutral          - C atoms that have a covalent bond to at least one
                         atom of class I or two or more atoms from class II
                         or III; atoms; S, F, P, and metal atoms in all cases
 VII  Neutral-donor    - C atoms that have a covalent bond with only one
                         atom of class III
VIII  Neutral-acceptor - C atoms that have a covalent bond with only 
                         one atom of class II
For each pair of contacts the state of legitimacy is shown below:

Legend:
+, legitimate
-, illegitimate
------------------------------------------------------------
  Atomic class           I  II  III   IV   V   VI  VII  VIII
------------------------------------------------------------
   I  (Hydrophilic)      +   +    +    -   +   +    +    +
  II  (Acceptor)         +   -    +    -   +   +    +    -
 III  (Donor)            +   +    -    -   +   +    -    +
  IV  (Hydrophobic)      -   -    -    +   +   +    +    +
   V  (Aromatic)         +   +    +    +   +   +    +    +
  VI  (Neutral)          +   +    +    +   +   +    +    +
 VII  (Neutral-donor)    +   +    -    +   +   +    -    +
VIII  (Neutral-acceptor) +   -    +    +   +   +    +    -
------------------------------------------------------------
Warning!
Atom classes for heterogroups are automatically assigned based on the atomic coordinates. However, in three cases (see below) the automatic assignment is currently ambiguous. In these cases, the user is advised to manually analyse the full list of contacts using LPC software.
1. Carbon atoms belonging to a 4-, 5- or 6-member ring are 
   considered "aromatic" (Class V) if the ring is approximately
   planar, and "hydrophobic" (Class IV) or "neutral" (Classes
   VI, VII, VIII) if the ring is non-planar.
2. The oxygen atom of a carbonyl or hydroxy group is considered
   "hydroxy" (Class I) if the CO bond is longer than 1.29 Å, and
   "carbonyl" (Class II) if shorter.
3. All nitrogen atoms are considered "hydrophilic" (Class I).

Please E-mail any questions and/or suggestions concerning this page to Vladimir.Sobolev@weizmann.ac.il